A pH-responsive anthocyanin-based hydrogel with colorimetric infection monitoring and antibacterial properties for wound healing

Chronic and infected wounds present significant clinical challenges due to fluctuating pH levels and persistent microbial contamination, which impede healing and increase the risk of complications. Traditional wound dressings lack the capacity to actively monitor and respond to changes in the wound microenvironment. In this study, we developed a multifunctional anthocyanin-based hydrogel that integrates pH-responsive antimicrobial release with real-time visual pH indication. Synthesized via a facile one-step free radical polymerization method, the hydrogel responds to microenvironmental pH shifts with visible color changes, enabling intuitive assessment of infection status. Simultaneously, it releases the antimicrobial agent chlorhexidine gluconate in a pH-dependent manner to enhance infection control. The hydrogel's structure and physiochemical properties, including swelling behavior, mechanical strength, and tissue adhesion, were thoroughly characterized. It also exhibited notable antimicrobial and antioxidant activities. In vitro studies demonstrated excellent cytocompatibility, while in vivo evaluation using a mouse alkali burn wound model revealed significant improvement in wound healing and inflammation reduction. This work provides a promising platform for intelligent wound care by combining diagnostic and therapeutic functionalities in a single, biocompatible material.